Pump dispensers are manually operated devices typically disposed on the top of a container of fluid for dispensing the fluid in a desired form from a dispenser nozzle. Dispensers of this type employ a cylindrical body structure, at least one piston and separate inlet and outlet ports individually controlled by separate means for opening and closing them.
The present invention is directed toward a new type of pump dispenser which employs combined inlet and outlet ports and a single means for opening and closing these ports in suitable sequence. This dispenser is characterized by a simplified structure having fewer and less complicated components and manufacturable at significantly reduced cost. This dispenser also has other advantages as described in more detail below.